As variações na retratibilidade no lenho das árvores são as principais causas dos defeitos de secagem, como o empenamento e fendilhamento das peças de madeira. Os tipos de madeira presentes em um tronco estão relacionados com as variações dessa importante propriedade física. Este trabalho teve como objetivo estudar a retratibilidade da madeira de sete espécies de eucaliptos. Os parâmetros de retratibilidade, bem como a sua variação na direção radial da medula em direção à periferia do tronco de sete espécies de eucaliptos, foram avaliados de acordo com a Norma brasileira. De modo geral, os resultados indicaram que as espécies de eucaliptos estudados possuíam madeira com elevada retratibilidade. À exceção das madeiras de Eucalyptus tereticornis e E. pilularis, as demais espécies estudadas apresentaram valores menores de retratibilidade na região próxima da medula.; The variation of the retratibility in lumber is the main cause of the occurrence of drying defects, especially those characterized by warped and split wood. The different wood types present in the stem are related to the variation of these important physical properties. This work aimed to study the retratibily of seven eucalypt species. The retratibility parameters such as the variation in the pith to bark direction in the peripheral of the trunk were studied according the Brazilian Standard for the seven eucalypts. In general the results showed that the species of eucalypts studied have a high retratibility. Except for Eucalyptus tereticornis and E. pilularis the others species studied showed lower values of retratibility in the pith region.

Este trabalho constitui a ultima parte do estudo que objetivou calcular o consumo de água em plantios de eucalipto. Nesta parte, modelou-se a resistência estomática em função das variáveis ambientais irradiância solar global, déficit de pressão de vapor e temperatura. Com a resistência estomática modelada a partir dos valores observados no artigo anterior, foi possível calcular a transpiração do eucalipto pelo método Penman-Monteith em alguns dias, nos períodos úmido e seco do ano. Verificou-se a existência da correlação entre a resistência estomática e as variáveis ambientais. Os modelos gerados nessa relação mostraram-se eficientes para calcular as variações diárias resistência estomática e também totais horários e diários de transpiração.; This paper concludes the last part of the work aimed to calculate water consumption in eucalypt plantations. Stomatal resistance was modeled as a function of the following ambient variables: global solar irradiance, vapor pressure deficit and temperature. Based on stomatal resistance modeled from the values observed in the first part of this work, eucalypt transpiration by the Penman-Monteith method could be calculated in some days during the humid and dry periods of the year. Correlation between stomatal resistance and ambient variables was verified. The models generated by this relation proved efficient in calculating the diurnal variation of stomatal resistance as well as hourly and daily transpiration totals.; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Celulose Nipo-Brasileira

The premature failure of a large agglomeration machine used for the annual production of 360,000 m(3) of eucalypt fiber panels was investigated to identify the nucleation and growth mechanisms of cracking in PH stainless steel belts (126 m x 2.9 m x 3.0 mm). These belts are used to compress a cushion composed of eucalyptus fibers and glue, being the pressure transmitted from the pistons by the action of numerous case-hardening steel rolls. Examination of the belt working interfaces (belt/rolls and belt/eucalypt fibers) indicated that the main cracking was nucleated on the belt/roll interface and that there is a clear relationship between the crack nucleation and the presence of superficial irregularities, which were observed on the belt/roll working surface. Used rolls showed the presence of perimetric wear marks and 2 mu m silicon-rich encrusted particles (identified as silicon carbide). Lubricant residues contained the presence of helicoidal wires, which were originated by the release of the stainless steel cleaning brush bristles, and 15 mu m diameter metallic particles, which were generated by material detachment of the belt. The presence of foreign particles on the tribological interface contributed to an increase of the shear stresses at the surfaces and...

In this study the strengths and weaknesses of eight filtering algorithms are evaluated by using the mean, standard deviation and RMSE metrics. Seven of these algorithms are implemented in the freeware software ALDPAT (Airborne LiDAR Data Processing and Analysis Tools) and the eighth, known as the Axelsson filter, in the commercial software Terrascan. The referred metrics are calculated by using DTM of topographic surfaces with quite different morphologies and vegetation covers. Forty-three of these surfaces, on circular plots of 400 m2 each, are covered by brushwood and unmanaged eucalypt forest with different stand characteristics. The mean tree density is around 1600 trees per hectare. The reference DTM for assessing the DTM produced by filtering full-waveform LiDAR data using the eight filtering algorithms are created with the help of a total station and geodetic GNSS receivers. The results show that the Axelsson and the so-called Polynomial Two Surface Fitting filters give the best results in terms of RMSE. Nonetheless, the results also show that all the tested filters are suitable for the filtering of full-waveform LiDAR data used in forestry related work, and collected over areas with great amount and high brushwood, chaotic eucalypt tree distribution and high tree density. The results obtained for a forest area with such characteristics – among which it should be mentioned a RMSE of 15 cm - are quite surprising.

Heat treatment of Pinus pinaster and Eucalyptus globulus woods, two important species in Portugal, was made in the absence of air by steaming, inside an autoclave, for 2 to 12h at 190 ºC to 210ºC. Mass losses increased with treatment time and temperature reaching 7.3% for pine and 14.5% for eucalypt wood. The wood behaviour with moisture was improved. The equilibrium moisture content decreased by 46% for pine and 61% for eucalypt, the dimensional stability increased (maximum anti-shrinking efficiency in the radial direction of 57% and 90% for pine and eucalypt respectively) and the surface wettability was lowered. In relation to mechanical properties, the modulus of elasticity was little affected (maximum decrease of 5% for pine and 15% for eucalypt) but the bending strength was reduced (by 40% at 8% mass loss for pine and 50% at 9% mass loss for eucalypt wood).
The variation of properties was related to treatment intensity and mass loss but significant improvements could already be obtained for a 3-4% mass loss without impairing the mechanical resistance. The response of eucalypt was higher than that of pinewood. Heat treatment of eucalypt wood shows an interesting potential to improve the wood quality for solid timber products.

Industrial eucalypt (E. globulus L.) kraft pulp was treated with two commercial xylanase preparations Ecopulp® TX-200A and Pulpzyme®
HC (endo-1,4- -xylanase activity; EC 3.2.1.8) and bleached by totally chlorine-free (TCF) three-stage hydrogen peroxide bleaching sequence,
without oxygen pre-delignification. The effect of enzymatic stage on pulp properties and bleachability has been studied and compared with
reference (control) pulps, processed without enzyme addition. The similar mode of enzymatic action was noted for both xylanase preparations.
Final brightness of 86% ISO was achieved after complete bleaching. Direct bleaching effect caused pulp brightening (by 1.2–1.5% ISO) and
delignification (by 7–10%) immediately after the enzymatic stage. The maximal bleach boosting was shown after the first peroxide stage and then
diminished, despite the progressive increase in delignification over the control. The loss in efficiency of xylanase treatment by the end of peroxide
bleaching was associated with specific behavior of xylan-derived chromophores, i.e., hexenuronic acids

We tested the influence of the aril on seed germination in controlled conditions and on the removal of M. champaca seeds in natural environment. Germination assays were kept at 25 ± 2 °C under continuous white light. Removal experiments were carried out in three "old" (39 to 62-years old) and three "new" (15-years old) eucalypt stands in Horto Florestal Navarro de Andrade, Rio Claro, SP. The results show that the aril inhibits the germination and the seeds exhibit a positively photoblastic reaction. We found higher seed removal in old eucalypt stands than the new ones, probably due to the higher density of rodents in the old stands. In the new stands, we found higher seed removal of arillated seeds by ants. Ants are important to remove the aril of seeds dropped by birds, not only enhancing seed germination but also preventing seed predation by rodents.

A pruned stand of eucalypt clone underwent five thinning treatments with the removal of different proportion of the planted trees, at different ages: a) 0% - unthinned, b) 35% at 55 months, c) 35% at 81 months, d) 70% at 81 months, removing sprouts in the thinned plant stumps and, e) 70% at 81 months, without coppice sprouts removal. By the age of 141 months, the Weibull distribution showed higher number of trees in the smallest diameter classes for the unthinned treatment. The 70% thinning, with thinned coppice sprouts removal, presented higher number of individuals in the largest diameter classes. Height and yield were the smallest with the removal of 70% of the trees at 81 months, maintaining coppice sprouts. The afterthinning periodic annual increment was greater by thinning 35% of the trees at 55 months resulting in greater number of trees in the largest diameter classes as compared to the other treatments. Yield was higher for the unthinned treatment. The results of this study indicated that thinning 70% of the trees at the age of 81 months, with coppice sprout removal, could be recommended to obtain trees of larger diameter for multiproduct.

High productivity of eucalypt plantations is the result of advances in research that have led to gradual improvements in intensive silvicultural technology. High productivity notwithstanding, eucalypt plantations remain the focus of environmental concerns. Our study aimed to compare the soil water regime, litter fall and nutrients dynamics either in a fragment of native forest or in an adjacent stand of growing eucalypt. We took field measurements during the first three years of eucalypt plantation in a sandy soil in the southeastern region of Brazil. Soil moisture and internal drainage were higher during the early stages of growth of the eucalypt stand, as compared with native vegetation. However, one and a half years after planting, available soil water was similar in both vegetations. Higher water availability under the eucalypt stand during the first year occurs because of silvicultural operations (soil preparation and weed control) and the small size of eucalypt trees; these factors increase water infiltration and decrease transpiration. Total leaf fall, over the study period, was similar for both ecosystems; however, differences were observed in the winter and early spring of 2010. The transfer of nutrients to soil by leaf fall was similar except for N and S...

Ecological theory differentiates rainforest and open vegetation in many regions as functionally divergent alternative stable states with transitional (ecotonal) vegetation between the two forming transient unstable states. This transitional vegetation is of considerable significance, not only as a test case for theories of vegetation dynamics, but also because this type of vegetation is of major economic importance, and is home to a suite of species of conservation significance, including the world’s tallest flowering plants. We therefore created predictions of patterns in plant functional traits that would test the alternative stable states model of these systems. We measured functional traits of 128 trees and shrubs across tropical and temperate rainforest – open vegetation transitions in Australia, with giant eucalypt forests situated between these vegetation types. We analysed a set of functional traits: leaf carbon isotopes, leaf area, leaf mass per area, leaf slenderness, wood density, maximum height and bark thickness, using univariate and multivariate methods. For most traits, giant eucalypt forest was similar to rainforest, while rainforest, particularly tropical rainforest, was significantly different from the open vegetation. In multivariate analyses...

This work aimed the evaluation of 15 (fifteen) provenances of three eucalypt species: Eucalyptus cloeziana, Eucalyptus grandis and Eucalyptus saligna. The trees were 31 years old and the test was developed in the campus of the Universidade Federal de Lavras. Six particleboards for each provenance were made by using the residues generated in the veneer production of this material. It was used urea-formaldehyde at 8% resin level and paraffin at 1%, both according to their respective solid content. The boards were produced by using a pressing cycle with temperature of 160 ºC, specific pressure of 40kgf/cm2 and pressing time of 8 minutes. From the results, it was concluded that the specie Eucalyptus saligna was the best one in terms of water absorption. The 43 provenance of Eucalyptus grandis showed the best development of thickness swelling. Superior results of compression and elastic modulus were found to Eucalyptus cloeziana. The provenance of number 10695 of the specie Eucalyptus grandis presented the best results for elastic and rupture modulus. In general, the provenance 10695 and species of Eucalyptus grandis showed the greatest potential for production of particleboard.; Com este trabalho, objetivou-se fazer a avaliação de 15 procedências de espécies de Eucalyptus cloeziana...

L.W. Braithwaite and co-researchers hypothesised that the population density and diversity of the arboreal marsupial fauna of the eucalypt forests near Eden, New South Wales were primarily determined by the concentrations of nitrogen, phosphorus and potassium in the mature foliage of the eucalypts. I investigated this hypothesis in relation to the Greater Glider Petauroides votans. The first main objective of my study was to examine why population densities of P. votans are low in eucalypt forests with
relatively low concentrations of nutrients in their mature foliage and high in eucalypt forests with relatively high concentrations of nutrients in their mature foliage. Initially, several a priori hypotheses were
proposed that could account for the observed population densities of P. votans in these forests, and these were tested at two forest sites in south-eastern N.S.W. by studying and comparing the ecology of P. votans
at these sites. One site of 24.6 ha at Wadbilliga carried four species of
eucalypt (E. dalrympleana, E. fastigata, E. radiata, E. viminalis}.
These had high concentrations of N and P in their mature foliage when compared to the range of values known for foliar N and P in this genus. The other site of 50.1 ha was at Morton and consisted of 40.3 ha of two
species of eucalypts...

High productivity of eucalypt plantations is the result of advances in research that have led to gradual improvements in intensive silvicultural technology. High productivity notwithstanding, eucalypt plantations remain the focus of environmental concerns. Our study aimed to compare the soil water regime, litter fall and nutrients dynamics either in a fragment of native forest or in an adjacent stand of growing eucalypt. We took field measurements during the first three years of eucalypt plantation in a sandy soil in the southeastern region of Brazil. Soil moisture and internal drainage were higher during the early stages of growth of the eucalypt stand, as compared with native vegetation. However, one and a half years after planting, available soil water was similar in both vegetations. Higher water availability under the eucalypt stand during the first year occurs because of silvicultural operations (soil preparation and weed control) and the small size of eucalypt trees; these factors increase water infiltration and decrease transpiration. Total leaf fall, over the study period, was similar for both ecosystems; however, differences were observed in the winter and early spring of 2010. The transfer of nutrients to soil by leaf fall was similar except for N and S...